不同断奶时间和体重的仔猪对简单饲粮和复杂饲粮的反应

用72头仔猪研究了断奶时间、断奶体重和饲粮类型对仔猪断奶后生产性能的影响。仔猪分别在25、35和45日龄断奶，每个日龄组选大、中、小三种体重猪各8头，分成二组。分别饲喂玉米一豆饼简单饲粮和含3％乳清粉、2％全脂奶粉和3％鱼粉的复杂饲粮。试验至70日龄结束。结果表明，随断奶日龄提高，70日龄体重（FW）和饲料利用率（FCR）提高（P＜0．01），但35与25日龄断奶差异不显著（P＞0，05）；25日龄断奶猪的血清尿素氧含量极显著（P＜0．01）高于35和45日龄组。随断奶体重增加，FW和采食量增加（P＜0．01），但是FCR没有明显改善（P＞0.05）；大体重猪的血清脲氮明显（P＜0.05）低于中、小体重。与复杂饲粮比较，使用简单词粮时，仔猪FW、采食量、FCR均明显下降，而血清尿素氮明显上升（P＜0．01）。水平组合比较表明，断奶早或体重小而喂复杂饲粮的猪与断奶晚或／和体重大而喂简单饲粮的猪具有相近的生长成绩。回归分析表明，断奶体重比断奶日龄对生长性能的影响更大；采食量是影响断奶后生长性能的关键因素。

THE RESPONSE OF PIGS WITH DIFFERENT WEANING AGE AND WEANING WEIGHI TO SIMPLE OR COMPLEX DIET

This trial studied the difference of simple or complex diet topromote performance of pigs with different weaning age and weight.Pigs wereweaned at 25, 35 and 45 d aud 8 pigs of leayier, middle and lighter bodyweigbtwithin a age group were switched to simple diet (SD) of corn and soybean meal andcomplex diet (CD) consisted of corn, wheat, soybean meal, 3% dried whey, 2% wholemilk and 3% fish meal to the end of experiment at pigs' age of 70 d. Pigs weanedat 45 d had better performanee (P<0.01) than pigs of 35 or 25 d. There was noperformance difference for pigs of d 35 and 25. As weaning weight of same ageincreased, performance was improved (P<0.01). Pigs fed CD had better performancethan those fed SD (P<0.01). Interactions of age, weight and diet indicated thatFigs weaned earlier or with small weaning weight but fed CD lad similarperformance to those weaned later or/and with large weight but fed SD. Regressionanalyses showed that weaning weight was muel more important for pigs' postweaningperformance than weaning age and that feed intake was a key factor influencingpigs' performance, The results demonstrated that diet high in nutritive value beprovided to pigs, especially those weaned earlier or with lighter weight, toincrease pigs' perfcrmance.